Electrical inductive apparatus



Dec. 29, 1942. A. WINTHER ETAL 2,306,582

ELECTRICAL INDUCTIVE APPARATUS Filed MaICh 19, 1941 I 2 Sheets-Sheet l Dec. 29, 1942. A w H ET AL 2,306,582

ELECTRICAL INDUCTIVE APPARATUS Filed March 19, 1941 2 Sheets-Sheet 2 FIGS.

I9 W 49 3 3a 4/ 45 35 2a 5/ PatentedDeaZfllQdZ UNITED STATES PATENT ELECTRICAL INDUCTIVE APPARATUS Anthony Winther, Kenosha, Wia, and

Whit-her, Waukegan, Ill

P. Winther, as trustee Application March 19, 1941, Serial No. 384,218;

9 Claims. (01. 172-284) This invention relates to electrical inductive apparatus, and with regard to certain more speciilc features to eddy-current machines, including brakes, slip clutches and the like.

Among the several objects of the invention may be noted the provision of an improved field concentrating member of relatively low inertia; the provision of apparatus of the class described which provides for high capacity at various speeds; and the provision of apparatus of the class described in which a very simple form of fastening is used for certain flux-concentrating members. Other objects will be in part obvious and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and arrangements of parts which will be exemplified in the structures hereinafter described, and the scope of the application of which will be indicated in the following claims.

In the accompanyins drawings, in which are illustrated several of various possible embodiments of the invention,

Fig. l is an end view, parts being broken away;

Fig. 2 is a vertical section taken on line 2-4 of Fig. 1;

Fig. 3 is an enlarged detail section taken on line 3-4 of Fig. 1;

Fig. 4 is a fragmentary enlarged section taken on line H of Fig. 3;

Fig. 5 is a vertical section taken on line 5-5 of Fig. 2; and,

Fig. 8 is a view similar to Fig. 5, but enlarged mrther and showing an alternative form of cross section.

Similar reference characters indicate corresponding parts throughout the several views of the drawings.

- Referring to the drawings, numeral l indicates a shaft which, according to the present example, from time to time requires braking. The shaft has rotarybearingsi andiinheads'l and! respectively of a stationary inductor case, indicated generally at II. This case is prevented from rotating by a suitable fastening it which is ilxed to some suitable stationary object.

Keyed to the shaft I is a rigid but light hub or spider 15, which has a continuous peripheral ring I! spacedly notched out as indicated at It. In the notches it are set laterally extending rectangular bars 2|. The bars are held in the notches i! by welding. It will be seen from-the drawings that the width 01' the spider I! at the periphery is of the order of the cross sectional dimensions oi the bars 2!. Near their ends they m1". 1 assignorstclhrtin are joined to one another by small flat spacers 23, which are welded endwise between bars, to form annular bracing. These stabilize the bars axially sothat they do not rock sidewise. For greater rigidity this bracing may be integral with the bars, as by forming an integral circular casting of the bars and bracing. Also, the spacers may extend throughout the axial lengths of the bars to increase stillness.

The heads 1 and 9 are bolted at their edges to peripheral supporting members 25 and 21, respectively. These members are provided with peripheral L-shaped recesses 29 and iii, respectively, for receiving with a water-tight slip fit grooved water-carrying members 33 and 35, respectively, made of inductive iron. The grooves in said members 33 and 35 are shown at 3! and 39, respectively, and are directed inward from smooth outward inductive faces I and 43, respectively. Adjacent to the faces 4| and 43, at close clearances, are the inside surfaces of the bars I i. The grooves 31 and as are water-carrying, cooling passages. They are each provided with water stops it at the top.

The supporting members 25 and 21 are also provided with L-shaped recesses for peripheral coils l! and ii, respectively, which are enclosed on the outside by a ring member 53. Member BI is grooved as at 51 and handed as indicated at 55 to provide external water circulating passages 58. Suitable circulating means are provided for circulating water through the passage 51. Water stops I are provided in the upper passages 51.

Each side of the device, so far as water circulation is concerned, is similar to the other side, referring to the center line of Figs. 2 and 3. "Water for each side is brought in over a pipe 62 to one a side of the respective stop 60, passes around through the respective circular passage 58 to the other side of the stop 60, out over a pipe 54, into a cored portion 56 which leads to one side of stops 88, around the peripheral passages 31 to the other side of the stops 38, whence the water leaves by a cored passage 68 and an outlet 10. Passage 68 is separated from cored passage 66 by dividing wall 80. This type of circulation is mentioned in United States Patent 2,220,032, but it has not been applied to providing a series circulation of water around the outside and the inside of a given set of inductor bars, as herein.

The coils l! and ii are energized as desired by direct current. I toric, as shown at the bottom of Fig. 2 by dotted arrows. The flux is proportional to the ampere m resulting flux path 14 is,

turns in the coils l9 and 5| and passes through the bodies 33, 35, 25 and 21 and 53, and radially through the bars 2| Since the flux field is of substantially homogeneous toric form throughout the members 25 and 21, and since the bars 2| are spaced peripherally, it will be seen that this flux field is concentrated through the bars radially.

Between the bars 2| the air gap between members 33, 35 and 53 is too great for fiux transmission. Thus, ii the shaft I is turned and the bars 2| moved, there will be a condition of movement of the fiux concentrations, which has the efl'ect of varying the fiux in the members 33, 35 and 53, as the bars 2| sweep about through the space between these members. By varying the flux at given points in a body, eddy-currents are established which, by heating, furnish the energy for absorption by the circulating water. The energy is then carried oil. by the water circulating in passages 31, 39 and 51.

It will be seen that the application of the invention to a brake in which the spider I5 is slowed down by energy absorption in the frame II is exemplary and that the invention may be applied to any eddy-current apparatus. For example, either the spider |5 or the member I I may be the driving rotor of an eddy-current clutch.

It will be seen from the above that the spider l5 carries the spaced bars 2| in position parallel to the axis of the spider and that each bar at each end extends into a portion of the member 53 which in general has a C-shape embracing the bars, and also that the peripherally wound field winding 5| is adjacent to the ends of the bars 2| and in the base of the -shape. The peripherally wound field winding engenders a toric flux field which at all points interlinks the O- shaped section of the member 53 and bars 2| through which it passes radially.

In Fig. 6 is shown an alternative in which the bars 2| are tapered at both their inner and ,outer sides as indicated at 12, and are set into tapered notches in the ring I! for fastening purposes. These bars 2| are arranged so that the outer and inner areas, which act as magnetic poles adjacent the eddy-current surfaces on the outside of members 33 and 35 53, are substantially less than the flux conducting area at any point in the flux circuit. This is true of both forms of the invention shown in Figs. 5 and 6, but in Fig. 6, in addition, there is a higher flux concentration at the outer and inner sides of the bars 2| than at their center portions 15. It is intended in Fig. 6 that the section I5 shall be at least 30% greater than the section 18. In the drawings said section 15 is shown more than 30% greater than section 15. Thus the apparatus is designed for flux concentration at the outer and inner surfaces of the bars 2|, and no other section of the flux path should be any smaller than shown at 18. The fact that in Fig. 6 the thickness of the bars 2| at the center, as at 16, is greater than the thickness of the outer and inner portions 12 decreases the reluctance of the magnetic path through the bars in addition to providing substantial flux concentration at surfaces 18.

From the above it portant advantage of is a flux concentration will be seen that one imthe invention is that there between the outer surfaces of the bars 2| and the adjacent inductor surfaces of member 53 as well as between the inner surfaces of the bars 2| and the adjacent inductor surfaces of the members 33 and 35. The result and on the inside of member.

the ends of the bars, a

is a large capacity with a very low weight in the member which carries the bars 2|.

It will be seen that the C-shaped portions are peripherally smooth and unbroken at the faces both outside and inside of the bars, and in addition that these faces are at close clearances. This prevents undue dissipation of the fiux field as it emanates from the bar edges and is driven into the adjacent eddy-current members and additionally permits of bringing the water passages quite close to the heated suriaces with a result that energy means be dissipated at a high rate. All of these greatly increase the ability of the machine to operate at high capacities.

It is to. be understood that the terms spaced and separate" as used in the claims and in connection with the bars 2| do not mean that the bars have no mechanical connections such as the braces 23 or the equivalent, above described. These terms are intended to refer to the fact that the bars are spaced and separate, so far as their flux-concentrating outer and inner faces are concerned. Thus the bars might form part of an integral casting with webbed portions therebetween forming the mechanical equivalent of the braces 23.

In view of the above, it will be seen that the several objects of the invention are achieved and other advantageous results attained.

As many changes could be made in the above constructions without departing from the scope of the invention, it is intended that all matter contained in the above description or shown in the accompanying drawings shall be interpreted as illustrative and not in a limiting sense.

We claim:

1. Eddy-current apparatus comprising relatively movable members, one of said members comprising a spider, bars having peripherally spaced inner and outer faces and mounted upon said spider and having their lengths parallel to the axis of rotation of the spider, the other relatively movable member having a C-shaped radial section embracing the bars and a recess adjacent peripherally wound field coil in said recess, said field coil engendering a toric flux field interlinking said bars and said C-shaped section, said bars acting as fiux concentrators and being radially tapered down inside and outside, providing bar edge faces which have less area than the mid portions of the bars, the peripheral inner and outer surfaces of the cshaped member adjacent to the bars being smooth and unbroken and having a relatively close clearance at all points with respect to the tapered-down bar edge faces.

2. Eddy-current apparatus comprising relatively movable members, one of said members comprising a spider, bars having peripherally spaced inner and outer faces and mounted upon said spider and having their lengths parallel to the axis of rotation of the spider, the other relatively movable member having a C-shaped section embracing the bars and a recess adjacent the ends of the bars, a peripherally wound field coil in said recess, said field coil engendering a toric flux field interlinking said bars and said C-shaped section, the peripheral faces of the c-shaped member adjacent the bars being circularly smooth and at close clearances, peripheral water-circulating passages in the c-shaped member adjacent to said bars, both inside and outside of the latter, and means for circulating water serially through the outside and inside passages.

3. Eddy-current apparatus comprising relatively movable members, one of which comprises.

a spider having a peripheral ring, bars having peripherally spaced inner and outer faces, each of which centrally is attached to said periphery and positioned with its length substantially parallel to the axis of rotation of the spider, the other of said relatively movable members having two peripheral portions formed with C shaped radial sections open toward one another and embracing the ends of said bars, said O- shaped member also having peripheral spaces adjacent the ends of the bars, peripherally wound coils in said spaces, said coils engendering two toric flux fields interlinking the C-shaped members respectively and the bars.

.4. In an eddy-current apparatus, relatively movable members, one of said members comprising a spider, flux bars fastened to said spider and extending axially with respect thereto, said bars being peripherally spaced circularly at their inner and outer faces, the other relatively movable member being inductive and having a C- shaped radial section surrounding said bars to provide relatively close clearances outside and inside the faces, the peripheral surfaces of said C-shaped member adjacent to said clearances both inside and outside being circularly smooth, and a field coil nested in the C-shape and ar-- ranged to form a toric flux field interlinking said C-shaped member and said faces.

5. In eddy-current apparatus, relatively movable members, one of said members comprising a spider, flux bars fastened to said spider and extending axially with respect thereto, said bars being peripherally spaced at their inner and outer faces, the other relatively movable member being inductive and having a C-shaped radial section surrounding said bars to provide relatively close clearances outside and inside the faces, the peripheral surfaces of said C-shaped member adjacent to said clearances both inside and outside being circularly smooth, and a field coil nested in the C-shape and arranged to form a toric flux field interlinking said C-shaped member and said bars, said bars being tapered down radially to their outside and inside faces whereby a substantial flux concentration is effected at said bar faces.

6. Eddy-current apparatus comprising relatively movable members, one of which consists in a spider having a periphery, bars each of which centrally is attached to said periphery and positioned with its length substantially parallel to the axis of rotation of the spider, the inner and outer edges of said bars being tapered down to present peripherally spaced edge faces of less width than the centers of the bars, the other of said movable members having two circular members each of c-shaped radial section and presenting inner and outer smooth peripheral surfaces closely adjacent respectively to the inner and outer faces of said bars and on both sides of the spider, peripherally wound coils respectively in said O-shaped members providing toric flux fields passing through said smooth surfaces and radially through the spaced faces.

7. Eddy-current apparatus comprising relatively movable members, one of which consists in a spider having a periphery, bars peripherally spaced at their inner and outer faces each of which centrally is attached to said periphery and positioned with its length substantially parallel to the axis of rotation of the spider, the other of said movable members having two members each of C-shaped radial section, and presenting inner and outer smooth peripheral surfaces closely adjacentrespectively to the inner and outer faces of said bars and on both sides of the spider, peripherally wound coils respectively in said 0- shaped members providing toric flux fields passing through said smooth surfaces and radially through the spaced faces.

8. Eddy-current apparatus comprising relatively movable members, one of which consists in a spider having a single narrow peripheral rim, bar-like magnetic members which are relatively long axially and each of which is relatively narrow in cross sectional dimensions .as compared with its length, each of said bar-like members being substantially centrally attached to the rim and positioned with its length substantially parallel to the axis of rotation of the spider, the narrowness of the rim of the spider in axial section being of the order of the cross sectional narrowness of each bar-like portion.

9. Eddy-current apparatus comprising relatively movable members, one of which consists in a spider having a single narrow peripheral rim, bar-like magnetic members which are relatively long axially and each of which is relatively narrow in cross sectional dimensions as compared with its length, each of said bar-like members being substantially centrally attached to the rim and positioned with its length substantially parallel to the axis of rotation of the spider, the narrowness of the rim of the spider in axial section being of the order of the cross sectional narrowness of each bar-like portion, the other relatively movable member having two circular members each of which is of C-shaped radial section closely embracing substantially half the axial lengths of the bar-like portions and spaced apart only enough to accommodate therebetween said narrow peripheral rim of the spider.

ANTHONY WIN'I'HER. MARTIN P. WINTHER. 

